Question 1

Question 2Distinguish between the following pairs:(a) Exocrine and endocrine glands (secretory substance and example)(b) Enzymes and hormones (mode of transport and target organ)(c) Nervous control and hormonal control (transmission and effect)(d) Diabetes mellitus and diabetes insipidus (cause and symptoms)(e) Addison's disease and Cushing's syndrome (cause and sugar level)

Accepted Answer

(a) Difference between exocrine and endocrine glands (secretory substance and example):Exocrine glandsEndocrine glandsExocrine glands secrete their products like sweat, enzyme, mucus, sebum, saliva, milk, etc. into ducts.Endocrine glands secrete their products, known as hormones, directly into the bloodstream.Examples of exocrine glands are Sweat glands, Salivary glands, Sebaceous glands, etc.Examples of endocrine glands are Thyroid, Pituitary, Adrenal, Pancreas.(b) Difference between enzymes and hormones (mode of transport and target organ):EnzymesHormonesEnzymes function intracellularly or within the confines of specific organs. They are not released into the bloodstream.Hormones are released into the bloodstream by endocrine glands.Enzymes do not have target organs. Instead, they act on their substrates at the cellular level and are highly specific for the reactions they catalyze.Hormones have specific target organs or tissues usually away from their source.(c) Difference between nervous control and hormonal control (transmission and effect):Nervous controlHormonal controlEffect is only short-lived.Effect is short term or long lasting.Transmitted electro-chemically through nerve fibres and chemically across synapses.Transmitted chemically through blood.(d) Difference between diabetes mellitus and diabetes insipidus (cause and symptoms):Diabetes mellitusDiabetes insipidusCaused due to insufficient secretion of insulin.Caused due to insufficient secretion of anti-diuretic hormone (ADH)High concentration of sugar in blood.No sugar in urine(e) Difference between Addison's disease and Cushing's syndrome (cause and sugar level):Addison's diseaseCushing's syndromeCaused due to hyposecretion of cortisoneCaused due to hypersecretion of cortisoneLow blood sugar levelHigh blood sugar level

Question 2

Question 10The hormone which stimulates the breakdown of glycogen in the liver to glucose is:GlucagonSomatostatinInsulinNone of these

Accepted Answer

GlucagonReason — Glucagon is responsible for breakdown of glycogen in the liver to glucose. It increases the level of glucose in blood.

Question 3

Question 11John tried to match the hormones with the disorders caused due to their hyposecretion. He tabulated the pairs as follows:HormonesDisorders caused due to hyposecretionPDiabetes mellitusQDiabetes insipidusIdentify the correct pairs of hormones.P - Insulin, Q - VasopressinP - Prolactin, Q - InsulinP - Insulin, Q - GlucagonP - Thyroxine, Q - Adrenaline

Accepted Answer

P - Insulin, Q - VasopressinReasonThe function of insulin is to regulate blood sugar levels and its hyposecretion causes diabetes mellitus (high blood sugar). The function of vasopressin is to help kidney in reabsorption of water and its hyposecretion causes diabetes insipidus.

Question 4

Question 3Name the following:(a) Three hormones secreted from Islets of Langerhans of pancreas.(b) Two types of cortical hormones.(c) Six hormones secreted from anterior pituitary.(d) Two hormones secreted from posterior pituitary.(e) The emergency hormone.(f) Diseases caused due to hypothyroidism.(g) Symptoms of cretinism.(h) Abnormalities caused due to hypersecretion of growth hormone.

Accepted Answer

(a) Three hormones secreted from islets of Langerhans of pancreas are —InsulinGlucagonSomatostatin(b) Two types of cortical hormones are —GlucocorticoidsMineralocorticoids(c) Six hormones secreted from anterior pituitary are —Growth hormone (somatostatin)ProlactinAdreno-corticotropic hormone (ACTH)Thyroid stimulating hormone (TSH)Follicle stimulating hormone (FSH)Luteinizing hormone (LH)(d) Two hormones secreted from posterior pituitary are —Antidiuretic hormone (ADH) or VasopressinOxytocin(e) The emergency hormone is —Adrenaline(f) Diseases caused due to hypothyroidism —Simple goitreCretinismMyxoedema(g) Symptoms of cretinism —Mental retardationDwarfism(h) Abnormalities caused due to hypersecretion of growth hormoneGigantismAcromegaly

Question 5

Question 4Write the main function of each of the following hormones.HormonesFunctions(a) Thyroxine...............(b) Adrenaline...............(c) Insulin...............(d) Glucagon...............(e) Vasopressin...............

Accepted Answer

HormonesFunctions(a) ThyroxinePromotes tissue metabolism, growth and differentiation.(b) AdrenalineCauses stimulation of sympathetic nervous system. Prepares body for any emergency.(c) InsulinReduces the blood sugar level.(d) GlucagonIncreases the blood sugar level.(e) VasopressinIncreases reabsorption of water from kidneys, contraction of blood vessels causing rise in blood pressure.

Question 6

Question 6If you stand to make your maiden speech before a large audience, your mouth dries up and heart rate increases. What brings about these changes?

Accepted Answer

When we stand to make our maiden speech before a large audience, our mouth dries up and heart rate increases and it is due to secretion of adrenaline hormone by adrenal glands. Adrenaline is the hormone which prepares the body to meet any emergency situation. Adrenaline makes the heart beat faster. At the same time, it stimulates the constriction of the arterioles of the digestive system reducing the blood supply of the digestive system which makes the mouth dry.

Question 7

Question 7Given below is a table designed to give the names of the glands, the hormones produced, their chief functions, the effects of over secretion and under secretion in respect of thyroid, pituitary and pancreas. Fill up the blanks 1-13.S.No.Source Gland cellsHormone producedChief functionEffect of oversecretionEffect of undersecretion1.(1) ...............Thyroxine(2) ...............(3)...............(4)...............2.Beta cells of Islets of Langerhans(5) ...............Promotes glucose utilisation by the body cells(6) ...............(7) ...............3.(8) ...............Growth hormone(9) ...............(10) ...............Dwarfism4.(11)...............VasopressinIncreases reabsorption of water from kidney tubules(12) ...............(13) ...............

Accepted Answer

S.No.Source Gland cellsHormone producedChief functionEffect of over secretionEffect of under secretion1.ThyroidThyroxineRegulates basal metabolismExophthalmic goiterSimple goiter, cretinism in children and myxoedema in adults2.Beta cells of Islets of LangerhansInsulinPromotes glucose utilization by the body cellsHypoglycemiaDiabetes mellitus3.Anterior pituitaryGrowth hormonePromotes growth of the whole bodyGigantismDwarfism4.Posterior pituitaryVasopressinIncreases reabsorption of water from kidney tubuleMore concentrated and less amount of urine, Elevation of blood pressureDiabetes insipidus

Question 8

Question 8Complete the following table by filling in the blanks numbered 1 to 7.GlandHormone secretedEffect on body(1) ...............(2) ...............Regulates basal metabolismPancreas ("beta" cells)(3) ...............Controls blood sugar(4) ...............(5) ...............Increases heart beat(6) ...............Thyroid stimulating hormone(7)...............

Accepted Answer

GlandHormone secretedEffect on bodyThyroidThyroxineRegulates basal metabolismPancreas ("beta" cells)InsulinControls blood sugar levelAdrenal glandAdrenalineIncreases heart beatAnterior pituitaryThyroid stimulating hormoneStimulates thyroxine secretion

Question 9

Question 9Complete the following table by filling in the blank spaces numbered 1 to 8.GlandSecretionsEffect on body(1) ...............Oestrogen(2) ...............Alpha cells of islets of Langerhans(3) ...............(4) ...............(5) ...............(6) ...............Protruding eyes(7) ...............(8) ...............Gigantism

Accepted Answer

GlandSecretionsEffect on bodyOvaryOestrogenDevelopment of secondary sexual characteristicsAlpha cells of islets of LangerhansGlucagonRaises blood sugar levelThyroidHypersecretion of thyroxineProtruding eyesAnterior pituitaryHypersecretion of Growth hormoneGigantism

Question 10

Question 1Study the diagram given below and then answer the questions that follow:(a) Name the cells of the pancreas that produce (1) glucagon (2) insulin.(b) State the main function of (1) glucagon and (2) insulin.(c) Why is the pancreas referred to as an exo-endocrine gland?(d) Why is insulin not given orally but is injected into the body?(e) What is the technical term for the cells of the pancreas that produce endocrine hormones?(f) Where in the body is the Pancreas located?

Accepted Answer

(a) Glucagon is produced by the Alpha cells of the islets of Langerhans.Insulin is produced by the Beta cells of the islets of Langerhans.(b) The main function of Glucagon is to raise the blood glucose levels by stimulating the breakdown of glycogen to glucose in the liver.The main function of Insulin is to maintain the levels of glucose (sugar) in the blood.(c) Exocrine glands are those glands which deliver their secretions to the target through ducts. An endocrine gland is one which does not pour its secretions into a duct but directly into the blood. As an exocrine gland the pancreas secrete pancreatic juices into the duodenum for digestion. As an endocrine gland, it has special groups of hormone-secreting cells called Islets of Langerhans which are scattered in the entire gland. The islet cells produce three hormones — insulin, glucagon and somatostatin which are poured directly into the blood. Hence, the pancreas is an exo-endocrine gland.(d) Insulin is not administered orally because the digestive juices degrade insulin making it ineffective. Hence, to avoid its degradation, Insulin is injected into the body.(e) Islets of Langerhans(f) The Pancreas is located in the abdomen behind the stomach.

Question 11

Question 5Identify the odd one in each of the following and mention what the rest are:(a) Larynx; glucagon; testosterone; prolactin(b) Adrenaline; penicillin; insulin; thyroxine(c) Stomach; ileum; liver; adrenaline(d) TSH; GH; ADH; insulin(e) Iodine; cretinism; goitre; myxoedema

Accepted Answer

(a) Larynx is the odd one here because glucagon; testosterone and prolactin are hormones whereas Larynx is the sound box.(b) Penicillin is the odd one here because adrenaline; insulin; thyroxine are hormones whereas Penicillin is an antibiotic.(c) Adrenaline is the odd one here because stomach, ileum and liver are the organs of the digestive system whereas Adrenaline is a hormone.(d) Insulin is the odd one here because TSH, GH, ADH are the hormones secreted by the pituitary gland whereas Insulin is secreted by the pancreas.(e) Iodine is the odd one here because cretinism, goitre, myxoedema are the conditions which occur due to undersecretion of thyroxine (Hypothyroidism) whereas Iodine is required for the synthesis of thyroxine hormone.

The Endocrine System

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